Validity and reliability of palatal rugae morphometric assessment with 3D laser scanned models

Aim: To assess the reliability and validity of morphometric features on 3D digital models produced by scanning maxillary dental casts of Malaysian Malay subjects. Methods: Dental casts of 20 subjects were scanned using a 3D laser scanner (Next Engine Inc., Santa Monica, California, USA). The palatal rugae morphometric features were assessed on the resulting 3D models using 3-Matic Research 9.0 software (Materialise NV, Heverlee, Belgium). The assessments were repeated by the first and second authors to assess the intra- and interexaminer reliability, respectively. Rugae morphometric features were also evaluated on the conventional plaster models to assess the validity of the 3D method. Results: Kappa values of the validity ranged from 0.807 to 0.922 for rugae shape, size category and direction. The intraclass correlation coefficient (ICC) for rugae number validity was 0.979. For intra-examiner reliability, kappa values ranged from 0.716-1.000 for rugae shape, size category and direction. The ICC for rugae number intra-examiner reliability was 0.949. Kappa values of interexaminer reliability for rugae shape, size category and direction were 0.723-885, while the ICC of rugae number was 0.896. Conclusion: Palatal rugae analyses on 3D digital models scanned by the 3D Next Engine laser scanner using 3-Matic Research 9.0 software are valid and reliable.

Early Maxillary Dentoalveolar Changes in Children with Unilateral Cleft Lip and Palate After Palatal Repair: A Pilot Study

Objective To assess early maxillary dentoalveolar changes in children with unilateral cleft lip and palate (UCLP) up to 6 months after palatoplasty. Design Pilot study. Patients and Participants Eight children with UCLP at the age of 18 to 30 months, who were awaiting palatal repair, were included. Interventions All participants with repaired lip were scheduled for palatal repair between 18 and 24 months by Bardach's technique. Main Outcome Measure(s) Arch widths, arch depths, and arch perimeter was measured on 32 dental casts of 8 participants at 4 time points: just prior to palatal repair (T1), 1 month (T2), 3 months (T3), and 6 months (T4) after palatal repair. Manual method using digital vernier caliper (Zhart, India) was used for model analysis. Intraexaminer reliability was also assessed. Results Only one examiner assessed all the dental casts after blinding. There was a significant decrease in the intercanine width (29.75 ± 1.98 mm at T1 to 26.42 ± 1.67 mm at T4; P < .001) and anterior arch depth (9.86 ± 1.07 mm at T1 to 8.29 ± 1.51 mm at T4; P < .001). Growth occurred in intertuberosity width (38.18 ± 1.40 mm at T1 to 39.76 ± 1.09 mm at T4; P < .001) and total arch depth (24.36 ± 1.21 mm at T1 to 26.79 ± 1.04 mm; P < .001) over 6 months post-surgery. Conclusions There was growth restriction in the anterior part of the palate, whereas the posterior region continued to grow after palatal repair. These changes were observable even in the early months after palatoplasty.

Grillz and Gold Teeth – Esthetic, Economics and Ethics

My laboratory has been providing services to a modest number of dental professionals for a while now. As part of prosthodontic work I have done, one has witnessed a generalised upsurge, albeit steady, in the request for gold inlays, followed by silver and grills overtime. The demand for these services is correlated with the location, period and ethos of the practice. Our practice has seen a drastic tapering down of requests during the Covid -19 period. Ultimately, there is a discernable driver for the demand of these services. We have also observed from dental casts that, the dentition appeared to be without any noticeable pathology. This implies that most patients requiring these prosthesis, have “virgin” teeth prepared. Being a small laboratory, our numbers, are insignificant compared to bigger laboratories. Additionally, unregistered laboratories and jewellers have entered this space and are providing ‘affordable’ alternatives. On a typical month, our laboratory fabricates a total of 320 prosthesis of which gold inlays, constitute about 60%, silver, 30% and grills, 10%. These numbers are an under-representation of the extent of this phenomenon and the potential ‘subdued’ and untapped market, especially during this fierce Covid -19 economic downturn. We hypothesise that we are witnessing the tip of an iceberg, and that under the right conditions, this grills and gold teeth epidemic will go beyond the tipping point. Given the cultural, economic and other factors, more and more youth will sustain the demand for these services in perpetuity.

Palatal vault morphometric analysis of the effects of two early orthodontic treatments in anterior open bite growing subjects: a controlled clinical study

Background The purpose of this study was to evaluate the palatal morphological changes in Anterior Open Bite (AOB) pre-pubertal subjects treated with Rapid Maxillary Expansion and Bite-Block (RME/BB) or Quad Helix with crib (QH/C) when compared with a Control Group (CG) by using Geometric Morphometric Analysis (GMM). Methods AOB group (AOBG) included 30 subjects (20 females, 10 males, mean age 8.1 ± 0.8ys) with dentoskeletal AOB. AOBG was divided in two subgroups according to the treatment strategy: RME/BB group (RME/BBg) included 15 subjects (10 females, 5 males, QH/C group (QH/Cg) comprised 15 subjects (10 females, 5 males). The two subgroups were compared with a CG of 15 subjects (10 females, 5 males) matched for sex, age, vertical pattern, and observation period. Digital upper dental casts were collected before treatment (T1) and at the end of the active treatment (T2). Landmarks and semilandmarks were digitized on dental casts and GMM was applied. Procrustes analysis and principal component analysis (PCA) were performed. Results At T2, RME/BBg when compared with QH/Cg evidenced no statistically significant differences. Instead, RME/BBg showed an increased maxillary transverse dimension and a decreased palatal depth when compared with CG. The comparison QH/Cg vs. CG demonstrated a slight transversal maxillary expansion. Conclusions RME/BBg showed significant changes in the transversal and vertical dimensions with a clear maxillary expansion and a decrease of the palatal depth when compared with QH/Cg and CG. QH/Cg showed a significant slight maxillary expansion and no variation in vertical and sagittal planes when compared with CG.

Comparison of commercially available preformed archwires with average natural arch forms

Objective: The research was carried out to compare the dimensions of commercially available preformed archwires with natural arch forms of Pakistani subjects. Methods: An observational study that lasted for 6 months was conducted at AFID, Rawalpindi. Fifty-two maxillary and mandibular dental casts of orthodontically untreated subjects (26 males and 26 females) were evaluated to obtain arch dimensions at the canines and first molar levels with the help of digital Vernier calipers. Bracket-archwire assembly was constructed to accurately measure widths from bracket-slot (BS) points at both the canine and molar levels, in an attempt to mimic clinical archwire-bracket interface. Canine and molar depths were also recorded for accurate estimation of the digitized archwire widths at the aforementioned levels. Results: The archwires evaluated for maxilla were significantly wider at canines (42.16 ±1.84mm, p = 0.000) and first molars (58.45 ± 1.33mm, p = 0.014) compared to the canine and molar dimensions of the dental casts obtained from subjects (37.61 ± 3.75mm, 55.68 ± 4.05mm respectively). For mandible, statistically significant differences were found at the canine level where archwires (34.75 ± 1.66mm, p = 0.000) exhibited greater dimensions than mean intercanine widths (29.33 ± 3.35mm) of the subjects. Conclusion: At present, commercially obtainable preformed archwires are inconsistent with the diverse arch forms manifested in a group of subjects with almost ideal occlusion. Therefore; utilization of these archwires may create unwarranted wider dimensions of the arch form, especially in the intercanine region which can influence post treatment retention, stability and facial esthetics. Continuous..

Comparison of Dental Surface Image Registration and Fiducial Marker Registration: An In Vivo Accuracy Study of Static Computer-Assisted Implant Surgery

This study compared the accuracy of static computer-assisted implant surgery (sCAIS) planned through dental surface image registration and fiducial marker registration. Stone models of 30 patients were converted into digital dental casts by using a desktop scanner. Cone-beam computed tomography (CBCT) was performed and superimposed to the digital dental casts with two methods: matching the dental surface images or matching the fiducial markers on a stereolithographic radiographic template. Following the implant planning, stereolithographic surgical guides were fabricated, and 56 fully guided implants were inserted by the same doctor. Deviations between planned and inserted implants were measured and compared using postoperative CBCT images. After adjustment for other potential influencing factors, compared with the fiducial marker registration group, significantly larger mean lateral deviations were noted in the dental surface registration group at both the implant platform and apex (p = 0.0188 and 0.0371, respectively). However, the mean lateral deviations for the dental surface registration (0.83 ± 0.51 mm at implant platform and 1.24 ± 0.68 mm at implant apex) were comparable to the literature. In conclusion, our findings indicate that although sCAIS planned using dental surface image registration was not statistically as accurate as that using fiducial marker registration, its accuracy was satisfactory for clinical use.

Palatal Vault Morphometric Analysis of the Effects of Two Early Orthodontic Treatments in Anterior Open Bite Growing Subjects: A Controlled Clinical Study

Background: The purpose of this study was to evaluate the palatal morphological changes in Anterior Open Bite (AOB) pre-pubertal subjects treated with Rapid Maxillary Expansion and Bite-Block (RME/BB) or Quad Helix with crib (QH/C) when compared with a Control Group (CG) by using Geometric Morphometric Analysis (GMM). Methods: AOB group (AOBG) included 30 subjects (20 females, 10 males, mean age 8.1 ± 0.8ys) with dentoskeletal AOB. AOBG was divided in two subgroups according to the treatment strategy: RME/BB group (RME/BBg) included 15 subjects (10 females, 5 males, QH/C group (QH/Cg) comprised 15 subjects (10 females, 5 males). The two subgroups were compared with a CG of 15 subjects (10 females, 5 males) matched for sex, age, vertical pattern, and observation period. Digital upper dental casts were collected before treatment (T1) and at the end of the active treatment (T2). Landmarks and semilandmarks were digitized on dental casts and GMM was applied. Procrustes analysis and principal component analysis (PCA) were performed.Results: At T2, RME/BBg when compared with QH/Cg evidenced no statistically significant differences. Instead, RME/BBg showed an increased maxillary transverse dimension and a decreased palatal depth when compared with CG. The comparison QH/Cg vs CG demonstrated a slight transversal maxillary expansion.Conclusions: RME/BBg showed significant changes in the transversal and vertical dimensions with a clear maxillary expansion and a decrease of the palatal depth when compared with QH/Cg and CG. QH/Cg showed a significant slight maxillary expansion and no variation in vertical and sagittal planes when compared with CG.

Changes in the Transverse Dimension of the Maxillary Arch of 5-Year-Olds Born With UCLP Since the Introduction of Nationwide Guidance

Objective: To determine whether the transverse dimensions of the maxillary arch of 5-year-old children with unilateral cleft lip and palate (UCLP) have changed following centralization of cleft services in the United Kingdom. Design: Retrospective cross-sectional study. Setting: Digital analysis of UCLP maxillary dental casts. Participants: All available maxillary dental casts from 5-year-old participants of the Clinical Standards Advisory Group (CSAG, N = 114) and Cleft Care UK (CCUK, N = 175) studies. Interventions: Quantitative measurements of the intercanine width (ICW), intermolar width (IMW), and the distance from the midline to the greater and lesser side canine (GC/LC) and greater side and lesser side second primary molar (GE/LE). Degree measurements of the greater and lesser arch form angles, arch length, anterior palatal depth (APD), and posterior palatal depth were also measured. Main outcome: Differences between the transverse dimensions of the maxillary arch for the CSAG and CCUK cohorts. Results: In 5 (ICW, IMW, LC, LE, and APD) of the 11 measurements, there was a statistically significant difference between the CSAG and CCUK cohorts. In all of these, the CCUK values were greater than CSAG. Conclusions: There have been small but positive improvements for the transverse maxillary dimensions since centralization of the UK cleft service.

The bite-type malocclusion classification – An extended Angle-method. Is the new classification reliable?

Objectives: As part in appraising the usefulness of the new bite-type method, a reliability assessment of the classification system was performed. Materials and Methods: Eighty-five selected dental casts were appraised by six operators and compared to a “Gold Standard.” The reliability of the bite-type method was assessed by double registrations of each of the nine bite-type classes by every operator. Results: An overall acceptable bite-type classification of all examiners existed. Correct assessments were found in 75–90% of the dental casts. Thus, the bite-type classification is a reliable method for categorizing sagittal malocclusions. Conclusion: The procedure could favorably replace the angle classification as it is more precise and detailed, without losing the strength of the basic angle system as an uncomplicated communication tool.

Equation for Tooth Size Prediction from Mixed Dentition Analysis for Taiwanese Population: A Pilot Study

Background: In mixed dentition analysis, estimation of the mesiodistal width of unerupted permanent canines and premolars is essential for successful diagnosis and treatment planning. The present study aimed to develop a simple linear equation to predict permanent tooth sizes from mixed dentition analysis for Taiwanese people. Methods: The sample comprised 200 dental casts, derived from Taiwanese patients (100 males and 100 females; age, 12–35 years). Mesial distal tooth widths were measured in dental casts with a digital caliper. A student’s t-test was conducted to detect tooth size correlations with gender-specific differences, as well as intra-arch counterparts. Standard linear regression was conducted to develop a simple equation representing predictions of canine-premolar relationships. Results: All teeth were not significantly different between the left and right sides, regardless of gender and upper or lower arches. In terms of types of teeth, males had larger tooth dimensions in both arches than females. New regression equations for estimating the dimensions of the unerupted canines and premolars in the Taiwanese population were developed. Conclusions: Using a sample of Taiwanese people, new models derived for females and males separately were developed, which should provide highly accurate predictions for unerupted canines and premolars in the Taiwanese population.